NEET Organic Chemistry Some Basic Principles and Techniques — Set 8

Question 1

In the Dumas method, 0.25 g of a compound gave 50 mL of $ \ce{N2} $ at STP. What is the percentage of nitrogen?

Accepted Answer

Mass of N = $ \frac{28}{22400} \times 50 = 0.0625 $ g. Percentage = $ \frac{0.0625}{0.25} \times 100 = 25\% $.

Question 2

Which compound with $ \ce{C5H8} $ has a degree of unsaturation of 2 and contains a triple bond?

Accepted Answer

Degree of unsaturation = $ \frac{2C + 2 - H}{2} = \frac{12 - 8}{2} = 2 $. $ \ce{CH3CH2C#CCH3} $ (pent-2-yne) has one triple bond (2 units), fitting $ \ce{C5H8} $.

Question 3

In the estimation of carbon and hydrogen, water is absorbed by which substance?

Accepted Answer

In the Liebig method, $ \ce{H2O} $ produced from hydrogen is absorbed by anhydrous $ \ce{CaCl2} $ (calcium chloride).

NEET Chemistry: Organic Chemistry Some Basic Principles and Techniques — Practice Set 8

Q1. In the Dumas method, 0.25 g of a compound gave 50 mL of \( \ce{N2} \) at STP. What is the percentage of nitrogen?

Q2. Which compound with \( \ce{C5H8} \) has a degree of unsaturation of 2 and contains a triple bond?

Q3. In the estimation of carbon and hydrogen, water is absorbed by which substance?

Q4. Which carbon in \( \ce{CH3CH2C(=O)NH2} \) has the highest electronegativity due to hybridization?

Q5. A compound with 10 \( \sigma \) bonds and 1 \( \pi \) bond has a molecular formula of \( \ce{C4H8} \). Which carbon has a bond angle of approximately 120°?

Q6. In paper chromatography, the separation of components depends on the difference in their:

Q7. In the Carius method, a compound weighing 0.24 g produces 0.47 g of \( \ce{AgCl} \) and 0.233 g of \( \ce{BaSO4} \). What is the ratio of chlorine to sulphur by mass?

Q8. What is the IUPAC name of \( \ce{CH3CH(CH3)CH2CH2OH} \)?

Q9. Which of the following compounds has the highest number of \( \sigma \) bonds?

Q10. In the estimation of carbon and hydrogen, 0.25 g of a compound gave 0.66 g of \( \ce{CO2} \) and 0.135 g of \( \ce{H2O} \). What is the empirical formula?